Topological Analysis of Electron Density in Graphene/Benzene and Graphene/hBN

Graphene is a modern material with unique properties which is used to create prototypes of gas, mechanical, and biological sensors. The non-covalent functionalization of graphene expands the scope of its practical application. Therefore, graphene-based van der Waals heterostructures are used to create various electronic devices. Thus, for a better understanding of physicochemical properties of graphene-based materials, it is necessary to study the role of van der Waals interactions in such structures in greater detail. This paper presents a study of the electron properties of structures such as graphene/benzene, graphene/graphene, and graphene/hBN within the framework of density functional theory with van der Waals interactions. Topological properties of electron densities were studied using the quantum theory of atoms in molecules. Visualization of the regions of van der Waals interaction and calculation of the charges of the regions describing the van der Waals interaction were possible due to the use of the reduced density gradient function. A comparison of the characteristics of the critical points of the electron density of graphene/graphene and graphene/hBN van der Waals heterostructures was also performed, which allowed us to compare the parameters of van der Waals interactions between different configurations of the systems under study.